Asp.net 核心 Blazor 服务器端 3.0 错误中的中间件重定向？

Question

我目前正在测试 asp.net core 3 blazor 服务器端应用程序。我在 f# 中构建了一个中间件扩展，并在 Startup class 的 Configure 方法中从 c# 调用它。它似乎最初尝试重定向，因为调用了正确的 url，但我收到一个错误页面，指出该页面未正确重定向。我在这里错过了什么。

F#:

type CheckMaintenanceStatusMiddleWare(next : RequestDelegate) =

    let _next = next

    member this.InvokeAsync(context : HttpContext) =

        let statusCheck = true
        if statusCheck
        then 
            Task.Run(fun arg -> context.Response.Redirect("/Maintenance"))
        else 
           _next.Invoke(context)

[<Extension>]
type CheckMaintenanceStatusMiddleWareExtensions() =

    [<Extension>]
    static member inline UseCheckMaintenanceStatus(builder : IApplicationBuilder) =

        builder.UseMiddleware<CheckMaintenanceStatusMiddleWare>()

C#

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            app.UseCheckMaintenanceStatus();

            var connectionString = Configuration.GetConnectionString("DefaultConnection");
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
                app.UseDatabaseErrorPage();
            }
            else
            {
                app.UseExceptionHandler("/Error");
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }



            app.UseHttpsRedirection();
            app.UseStaticFiles();

            //app.UseCookiePolicy();

            app.UseRouting();

            app.UseAuthentication();
            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
                endpoints.MapBlazorHub();
                endpoints.MapFallbackToPage("/_Host");
            });
        }

剃刀组件：

@page "/Maintenance"

<h3>Maintenance</h3>

@code {

}

Answer 1

重定向循环可能发生如下：

                                              (redirect-loop might happens)
Request Process Starts                       <---------------------------+
 |----->  CheckMaintenanceStatusMiddleWare                               |
              (check status)                                             |
                  if fail then redirect to '/Maintenance' -------------->|
                  else 
                       |----> go to inner middlewares by next(context)

为避免无休止的重定向循环，请检查当前路径是否已更改为/Maintenance:

if statusCheck && context.Request.Path.Value <> "/Maintenance" then
    ... redirect
else
    ... invoke inner middlewares

Asp.net 核心 Blazor 服务器端 3.0 错误中的中间件重定向？

Middleware redirect in Asp.net core Blazor server-side 3.0 error?

c#

asp.net

f#

asp.net-core

asp.net-core-3.0